The present invention relates generally to spheres marked with indicia for alignment purposes and, more particularly, to a method for marking spheres with indicia for alignment purposes, a device for imprinting the alignment indicia of the present invention on a sphere, and a sphere so marked.
The background information discussed below is presented to better illustrate the novelty and usefulness of the present invention. This background information is not admitted prior art.
There are many instances where a perfect alignment of a sphere on a surface is required. One of the easiest to understand examples is provided by a golf ball. Golf is a precision sport, in which competing golfers use many types of clubs to hit golf balls into a series of holes on a golf course using the fewest number of strokes. Golf balls are readily available marked with alignment indicia that act as guides, helping the golfer to strike the golf ball in the correct manner.
The object of the game is to get a golf ball from the area where the game begins, commonly referred to as the “teeing ground”, into a particular hole with the fewest number of strokes. A “round is based on playing a number of holes in a given order and typically consists of either eighteen holes that are played in the order determined by a golf-course's layout or of a nine-hole course. The game starts when a golfer strikes a golf ball with a club, referred to as teeing. For this beginning shot, golfers frequently suspend the ball on a “tee” prior to striking it. A tee is a small peg with a supporting surface area on which a golf ball is placed to elevate it slightly above the ground. After the first strike, once the ball comes to rest, the golfer strikes it repeatedly until the ball reaches the green. Once the ball is on the green, the ball is then “putted” using a golf club known as a “putter” to roll the ball across the green into the cup. The putter is used in short distance shots on or near the green. The goal of the putt is to get the ball in the hole.
To get the ball to move along the intended precise line of direction between the ball and the cup requires that: (1) the ball be struck so that the striking surface of the golf club remains strictly perpendicular to the direction of club head travel during the putting stroke, and (2) the club head must be moved along the precise direction line of the putt to avoid hitting the ball off-line or imparting an undesired roll to the ball. However, most golfers have difficulty properly aligning a putter club head with their golf ball. Proper putting alignment is a difficult aspect of the game but is required for accurate putting, which is necessary for a good golf score. Achieving proper putting alignment, often referred to as the “address position” is essential.
One way of assisting the golfer in the goal of getting the ball into the hole is to use golf balls that are provided with, what is referred to as, an “equatorial marking line” on the ball, so that a golfer can observe how straight the ball he just putted is rolling across the green. Such a line, like the equator of a sphere, is always a “great circle”. Such a line, may in general, be referred to in the art as an alignment line and may be a continuous line or a series of short lines. A ball marked with such an equatorial marking line, must be correctly positioned for striking. The proper position for striking a marked golf ball is to have the equatorial line positioned within a vertical plane that is simultaneously perpendicular to the horizontal plane, which can be approximated by a flat, level ground surface of the putting green, and to the face of the putter club, as the club strikes the ball. Another aid provided to golfers is a “putter target line.” The putter target line is a line drawn across the surface of a putter that is to be aligned with the equatorial line of the golf ball. If the alignment is done correctly and if the golfer is in his or her correct address position, the ball struck by the putter should roll across the green maintaining the equatorial line in a vertical position. If, however, the alignment was not correct, the golfer's address position was off, or if the putting stroke was not accurately directed, the ball will wobble out of verticality. This wobbling is most easily appreciated by watching the wobble of the equatorial line as the ball is traveling. Additionally, there may also be drawn on the ball one or more cross lines referred to as “squareness lines” so that a golfer may more easily maintain the putter face square with the ball.
In order for the golfer to be in correct alignment with the golf ball means that the golfer must position his or her eyes directly over the ball. This can be understood by drawing an imaginary line between a golfer's eyes and the golf ball. For correct alignment, the imaginary line must be vertical with respect to the ground surface and must bisect the ball along an imagined equatorial axis. In this position, the golfer's eyes are directly over the ball. This imaginary line is referred to as “line-of-sight.”